Rare Earth Shortages Revive Alternatives

There are rising concerns over China restricting exports of rare earth elements.

Such warnings have at least some validity. This is a big deal because rare earths -- a series of elements given their own section of the periodic table because of the unusual properties of electrons in their outer atomic shells -- are used in everything from smartphones and hybrid cars to smart bombs. Gadolinium (Gd) and thulium (Tm) are used in MRI and X-ray machines, while ytterbium (Yb) is a key component of most semiconductor lasers.

Early in the decade, when China controlled 95 percent of rare earth production, it cut prices on commodity exports of the lanthanide elements (which include Gd, Tm, and Yb). More recently, in the past 18 months, it has cut back on exports of virtually all such minerals.

When China cut back rare earth shipments in 2010 to large Japanese OEMs such as Sony and Matsushita, it was seen at first as a kind of cold war provocation regarding ocean rights. But by early this year, China had announced it was cutting back on rare earth exports for environmental reasons. Such arguments should be taken with a grain of salt, though rare earth mining does create radioactive tailings piles and contaminated slurries that have led to serious opposition to mine sites in nations such as Malaysia.

Supply panic stemming from the export cutting has spurred users to look for solutions. Mining sites in Nebraska, Australia, and Canada's Northwest Territories have considered resuming production. Those aren't bad options, because they'll receive a certain amount of environmental oversight.

Not as optimal are bootleg mining operations in Africa and Central Asia, which would raise problems of contamination and worker abuse. Consider what happened with coltan, a columbite-tantalite compound used to make capacitors in mobile phones, DVD players, and laptops. Serious problems at coltan mines in the Democratic Republic of the Congo were documented in one of this year's most eye-opening documentaries, Blood in the Mobile.

Luckily, OEMs need not get into a rare earth panic. A cover story in the Aug. 27 issue of Science News detailed efforts to find cheaper, more common alternatives to rare earths, particularly in high-performance magnet applications.

The Department of Energy's Ames Laboratory and scientists at Tohoku University in Japan are revisiting older magnetic materials from the mid-20th century, such as aluminum-nickel-cobalt compounds and thin films of iron and nitrogen, to offer high-performance magnets free of rare earths. For hybrid cars, scientists hope to optimize the use of the rare earth neodymium by turning to nanocomposite materials for stronger, more efficient permanent magnets.

A global rare earth market less dependent on China is probably a good thing, even if prices on the lanthanides rise by a few percentage points. But it's also good to see developers talk of replacing rare earths in many electronic applications. They may not be as rare in the earth's crust as their name implies, but the difficulty of mining and purifying rare earths makes them a manufacturing component ripe for replacement.